Flatworms, Roundworms, & Rotifers Chapter 34. Phylum Platyhelminthes Section 34.1.
KEY CONCEPT Roundworms have bilateral symmetry and shed their outer skeleton to grow.
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23.5 Roundworms KEY CONCEPT Roundworms have bilateral symmetry and shed their outer skeleton to grow.
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KEY CONCEPT Roundworms have bilateral symmetry and shed their outer skeleton to grow. Roundworms are protostomes with bilateral symmetry. pharynx. intestine. brain. cuticle. anus. tail. Roundworms shed their stiff outer skeleton as they grow. - PowerPoint PPT Presentation
Transcript of KEY CONCEPT Roundworms have bilateral symmetry and shed their outer skeleton to grow.
23.5 Roundworms
KEY CONCEPT Roundworms have bilateral symmetry and shed their outer skeleton to grow.
23.5 Roundworms
Roundworms shed their stiff outer skeleton as they grow.
• Roundworms are protostomes with bilateral symmetry.
brain
cuticle
pharynx
intestine
anus
tail
23.5 Roundworms
• Roundworms have a tough outer skeleton called a cuticle.– made of chitin– must be shed to grow
• Roundworms have a pseudocoelom, not completely lined by muscle.
• Roundworms reproduce sexually.
chitin
23.5 Roundworms
Many roundworms are parasites.
• Nearly every plant and animal species are parasitized by roundworms. – hookworms– pinworms– Guinea worms
